TEHRAN, Iran — Two Iranian lawmakers on Monday stepped up threats their country would shutter the strategic Strait of Hormuz, through which a fifth of the world’s crude flows, in retaliation for oil sanctions on Tehran.

The warnings came as EU nations agreed in Brussels on an oil embargo against Iran as part of sanctions over the country’s controversial nuclear program. The measure includes an immediate embargo on new contracts for Iranian crude and petroleum products while existing ones are allowed to run until July.

Iran has repeatedly warned it would choke off the strait if sanctions affect its oil sales, and two lawmakers ratcheted up the rhetoric on Monday.

Lawmaker Mohammad Ismail Kowsari, deputy head of Iran’s influential committee on national security, said the strait “would definitely be closed if the sale of Iranian oil is violated in any way.”

Kowsari claimed that in case of the strait’s closure, the U.S. and its allies would not be able to reopen the route, and warned America not to attempt any “military adventurism.”

Another senior lawmaker, Heshmatollah Falahatpisheh, said Iran has the right to shutter Hormuz in retaliation for oil sanctions and that the closure was increasingly probable, according to the semiofficial Mehr news agency.

“In case of threat, the closure of the Strait of Hormuz is one of Iran’s rights,” Falahatpisheh said. “So far, Iran has not used this privilege.”

Monday’s EU measure also includes a freeze on the assets of Iran’s central bank as part of sanctions meant to pressure Tehran to resume talks on its uranium enrichment, a process that can lead to making nuclear weapons. Iran insists its nuclear program is exclusively for peaceful purposes.

For its part, the United States has enacted, but not yet put into force, sanctions targeting Iran’s central bank and, by extension, the country’s ability to be paid for its oil.

Some 80 percent of Iran’s oil revenue comes from exports and any measures or sanctions taken that affect its ability to export oil could hit hard at its economy. With about 4 million barrels per day, Iran is the second-largest producer in OPEC.

Tensions over the strait and the potential impact on global oil supplies and also the price of crude have weighed heavily on consumers and traders.

Both the U.S. and Britain have warned Iran over any disruption to the world’s oil supply through he strait.

Another Iranian lawmaker, Ali Adyani, sought to downplay the latest EU move, describing it as a “mere propaganda gesture,” according to the semiofficial Fars news agency.

Former intelligence minister, Ali Falahaian, suggested Iran should stop all its crude exports “so that oil prices would go up and the Europeans’ sanctions would collapse.”

Threats to close the strait escalated during Iran’s naval exercises in the Persian Gulf in January. Iran plans more naval war games in February.